Smart logic device

ABSTRACT

A cognitive learning device includes inputs with each including an input path having a transistor device having a storage capacity. A circuit is responsive to the inputs and selects an input set in accordance with a current task, wherein the input set selected modifies a characteristic of the transistor device of one or more corresponding input paths to bias the input set for selection for subsequent accesses.

BACKGROUND Technical Field

The present invention generally relates to cognitive computing, and moreparticularly to devices and methods for computer learning using floatinggate transistors.

Description of the Related Art

Neural networks (NN) are a leading method for implementing machinelearning and training for cognitive computing. Cognitive computingprovides a capability for computers to learn. Cognitive computing is thesimulation of human thought processes in a computerized model. Cognitivecomputing involves self-learning systems that may employ data mining,pattern recognition and natural language processing to mimic the way thehuman brain works.

SUMMARY

In accordance with an embodiment of the present principles, a cognitivelearning device includes inputs with each including an input path havinga transistor device having a storage capacity. A circuit is responsiveto the inputs and selects an input set in accordance with a currenttask, wherein the input set selected modifies a characteristic of thetransistor device of one or more corresponding input paths to bias theinput set for selection for subsequent accesses.

Another cognitive learning device includes a plurality of inputs, eachinput including an input path. At least one transistor device isassociated with each input path, and the at least one transistor devicehas a storage capacity such that a threshold voltage of the at least onetransistor device is modified in accordance with access criteria. Acomparator circuit is responsive to the plurality of inputs and selectsan input set in accordance with a current task such that the input setselected modifies the threshold voltage of the at least one transistordevice to bias input paths associated with the input set for selectionfor subsequent accesses.

A method for employing a cognitive learning device includes randomlyselecting a path initially among a plurality of input paths, each havingat least one transistor; determining a correct input path for performinga current task; and modifying a threshold voltage of the at least onetransistor associated with the correct path to bias selection of thecorrect path in subsequent accesses.

These and other features and advantages will become apparent from thefollowing detailed description of illustrative embodiments thereof,which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The disclosure will provide details in the following description ofpreferred embodiments with reference to the following figures wherein:

FIG. 1 is a schematic diagram showing a comparator circuit with threeinputs in accordance with one illustrative embodiment in accordance withthe present principles;

FIG. 2 is a cross-sectional view illustratively showing a floating gatetransistor device in accordance with one embodiment of the presentprinciples;

FIG. 3 is a network diagram showing a network of cognitive learningdevices linked together and an illustratively selected path inaccordance with the present principles; and

FIG. 4 is a block/flow diagram showing a method for employing acognitive learning device in accordance with the present principles.

DETAILED DESCRIPTION

In accordance with the present principles, smart logic devices areprovided that learn a priority path or process sequence to be employedbased on previous actions or activity. Cognitive computing is employedto learn a best or most relevant algorithm, procedure, path or activitybased upon set criteria. In one example, a floating gate field effecttransistor (FET) or transistors are employed to change devicecharacteristics based upon previous circuit activity. For example, acomputer may be employed to identify an object type, such as cars,people, animals, etc. from images. In this example, an algorithm A isemployed to identify cars, algorithm B is employed to identify peopleand algorithm C is employed to identify animals in images. If a numberof cars seen by the computer is more frequent over a given time, thecomputer will be smart and check for cars first, rather than follow asame sequence for checking all three in a specific order. Usingfrequency or other criteria, a way to efficiently inform the computer asto which algorithm to perform first based on how often the algorithm hasbeen used for a given time can be achieved. An analog non-volatilerandom access memory (NVRAM) device or devices may be employed for thesepurposes.

Floating gate storage devices provide programmable weighting devices andremain consistent with complementary metal oxide semiconductor (CMOS)processing. In one embodiment, floating gate metal oxide semiconductor(MOS) devices are employed as weighting devices in a cognitive computingapplication.

It is to be understood that the present invention will be described interms of a given illustrative architecture; however, otherarchitectures, structures, substrate materials and process features andsteps may be varied within the scope of the present invention.

It will also be understood that when an element such as a layer, regionor substrate is referred to as being “on” or “over” another element, itcan be directly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” or “directly over” another element, there are no interveningelements present. It will also be understood that when an element isreferred to as being “connected” or “coupled” to another element, it canbe directly connected or coupled to the other element or interveningelements may be present. In contrast, when an element is referred to asbeing “directly connected” or “directly coupled” to another element,there are no intervening elements present.

The present embodiments may include a design for an integrated circuitchip, which may be created in a graphical computer programming language,and stored in a computer storage medium (such as a disk, tape, physicalhard drive, or virtual hard drive such as in a storage access network).If the designer does not fabricate chips or the photolithographic masksused to fabricate chips, the designer may transmit the resulting designby physical means (e.g., by providing a copy of the storage mediumstoring the design) or electronically (e.g., through the Internet) tosuch entities, directly or indirectly. The stored design is thenconverted into the appropriate format (e.g., GDSII) for the fabricationof photolithographic masks, which typically include multiple copies ofthe chip design in question that are to be formed on a wafer. Thephotolithographic masks are utilized to define areas of the wafer(and/or the layers thereon) to be etched or otherwise processed.

Methods as described herein may be used in the fabrication of integratedcircuit chips. The resulting integrated circuit chips can be distributedby the fabricator in raw wafer form (that is, as a single wafer that hasmultiple unpackaged chips), as a bare die, or in a packaged form. In thelatter case, the chip is mounted in a single chip package (such as aplastic carrier, with leads that are affixed to a motherboard or otherhigher level carrier) or in a multichip package (such as a ceramiccarrier that has either or both surface interconnections or buriedinterconnections). In any case, the chip is then integrated with otherchips, discrete circuit elements, and/or other signal processing devicesas part of either (a) an intermediate product, such as a motherboard, or(b) an end product. The end product can be any product that includesintegrated circuit chips, ranging from toys and other low-endapplications to advanced computer products having a display, a keyboardor other input device, and a central processor.

It should also be understood that material compounds will be describedin terms of listed elements, e.g., SiGe. These compounds includedifferent proportions of the elements within the compound, e.g., SiGeincludes Si_(x)Ge_(1-x) where x is less than or equal to 1, etc. Inaddition, other elements may be included in the compound and stillfunction in accordance with the present principles. The compounds withadditional elements will be referred to herein as alloys.

Reference in the specification to “one embodiment” or “an embodiment” ofthe present principles, as well as other variations thereof, means thata particular feature, structure, characteristic, and so forth describedin connection with the embodiment is included in at least one embodimentof the present principles. Thus, the appearances of the phrase “in oneembodiment” or “in an embodiment”, as well any other variations,appearing in various places throughout the specification are notnecessarily all referring to the same embodiment.

It is to be appreciated that the use of any of the following “/”,“and/or”, and “at least one of”, for example, in the cases of “A/B”, “Aand/or B” and “at least one of A and B”, is intended to encompass theselection of the first listed option (A) only, or the selection of thesecond listed option (B) only, or the selection of both options (A andB). As a further example, in the cases of “A, B, and/or C” and “at leastone of A, B, and C”, such phrasing is intended to encompass theselection of the first listed option (A) only, or the selection of thesecond listed option (B) only, or the selection of the third listedoption (C) only, or the selection of the first and the second listedoptions (A and B) only, or the selection of the first and third listedoptions (A and C) only, or the selection of the second and third listedoptions (B and C) only, or the selection of all three options (A and Band C). This may be extended, as readily apparent by one of ordinaryskill in this and related arts, for as many items listed.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes” and/or “including,” when usedherein, specify the presence of stated features, integers, steps,operations, elements and/or components, but do not preclude the presenceor addition of one or more other features, integers, steps, operations,elements, components and/or groups thereof.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper,” and the like, may be used herein for ease of description todescribe one element's or feature's relationship to another element(s)or feature(s) as illustrated in the FIGS. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the FIGS. For example, if the device in theFIGS. is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations), and the spatially relativedescriptors used herein may be interpreted accordingly. In addition, itwill also be understood that when a layer is referred to as being“between” two layers, it can be the only layer between the two layers,or one or more intervening layers may also be present.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another element. Thus, a first element discussed belowcould be termed a second element without departing from the scope of thepresent concept.

Referring now to the drawings in which like numerals represent the sameor similar elements and initially to FIG. 1, an illustrative cognitivecomputing circuit 10 includes a circuit responsive to one or more inputs24, such as a comparator device 12 capable of measuring differences involtage (or current) between input terminals 24. It should be understoodthat while a comparator device is illustratively shown in accordancewith one embodiment, other embodiments may include other circuit typesand configurations. In some examples, comparators 12 may include asensor circuit, a switching device or devices, logic gates, etc. Inother embodiments, part or all of the circuit 10 may include softwareelements or be part of a computer.

Initially devices in gate circuits 14, e.g., transistors 16, 18, onpaths A, B and C will have about a same threshold voltage (V_(T)).Transistors 16, 18 may include NVRAM devices, such as, e.g., floatinggate transistors or other devices that include storage features so thatan accumulated history of usage can be tracked or employed.

In one illustrative embodiment, the gate circuits 14 may include aplurality of transistor devices (e.g., NVRAM transistors). Thetransistors of the gate circuits 14 may include a p-type field effecttransistor (PFET) 16 and an n-type field effect transistor (NFET) 18.Depending on an input pulse to the gate device 14, either Vdd 20 orGround 22 is provided on the input line to the comparator 12.

Comparator 12 may randomly pick a path A, B or C. In one example, path Bis assumed to be picked randomly, initially, and the circuit 10 executespath B, path A, and then path C. However, upon execution of all paths,it is determined that the correct path was path C. NVRAMs in path C areselected and charge is stored in the NVRAM of path C. This can have theeffect of modifying the V_(T). In one embodiment, the V_(T) is increasedwith the selection or determination of path C.

In a next round, threshold voltages (V_(T)) of path C will be higher andwill be selected (instead of randomly) by comparator 12 more easily thanthe other paths (A, B). If path C is the correct path in the next round(of accessing comparator circuit 10), then the path C NVRAMs 16, 18 areselected again and V_(T) is increased further. If C is continually thecorrect path, the path C NVRAMs V_(T) will be higher than the rest andwill continue to be a starting point for the processing. If the patternshifts to B or A, the path NVRAMs will be selected and V_(T) will beincreased for the selected path(s).

In one embodiment, the selection of a new path may cause the thresholdvoltage to decrease in the other paths by permitting some discharging ofthe storage in the path NVRAMs. In some embodiments, a discharge orreset function may be provided to re-initiate the path NVRAMs.

The device 10 may be one of a plurality of devices 10 employed in acomputer device 30 or as part of a computer system. The computer deviceor system 30 preferably includes hardware for carrying out operationsand in particular includes integrated circuits. In other embodiments,combinations of hardware and software may be employed.

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Referring to FIG. 2, a floating gate transistor device 100 isillustratively shown with a planar device structure. However, thefloating gate transistor device 100 may be a vertical transistor, afinFET or any other transistor structure. The floating gate transistordevice 100 may be an analog device although digital devices may also beemployed. The device 100 includes a substrate 102. The substrate 102 maybe crystalline (e.g., monocrystalline). The substrate 102 may beessentially (i.e., except for contaminants) a single element (e.g.,silicon), primarily a single element (i.e., with doping), for example,silicon (Si) or germanium (Ge), or the substrate may be a compoundsemiconductor, for example, a III-V compound semiconductor (e.g., GaAs),SiC, or SiGe.

The substrate 102 may also have multiple material layers, for example, asemiconductor-on-insulator substrate (SeOI), a silicon-on-insulatorsubstrate (SOI), germanium-on-insulator substrate (GeOI), orsilicon-germanium-on-insulator substrate (SGOI). In one or moreembodiments, the substrate 102 may be a silicon wafer. In variousembodiments, the substrate is a single crystal silicon wafer. A singlecrystal silicon substrate may have a <100> or a <111> surface. In theembodiment shown, the substrate 102 includes a bulk substrate.

The substrate 102 may be doped to form source regions 104 and drainregions 106 in the bulk material of the substrate 102. The source region104 and drain region 106 may be doped by implantation, diffusion orepitaxially grown on the substrate and doped in-situ (during itsfabrication). The source/drain regions 104/106 may be n-doped orp-doped. The source/drain regions 104/106 may have a dopantconcentration in the range of about 1×10¹⁹ to about 1×10²² dopantatoms/cm³. In various embodiments, the source/drain regions 104/106include a same or different material than the substrate 102. It shouldbe noted that the positions of the source and a drain may beinterchanged.

A channel region 118 is disposed between the source/drain regions104/106 and below a floating gate structure 110. The channel region 118may be doped and may include one or more other dopant regions, e.g.,halo dopant regions, etc. The gate structure 110 includes a lower gatedielectric 108. The lower gate dielectric 108 may be grown or depositedby, e.g., atomic layer deposition (ALD) and/or chemical vapor deposition(CVD). The lower gate dielectric 108 may be silicon oxide, siliconnitride, silicon oxynitride, and/or a high-k material, including but notlimited to metal oxides such as hafnium oxide (e.g., HfO₂), hafniumsilicon oxide (e.g., HfSiO₄), hafnium silicon oxynitride(Hf_(w)Si_(x)O_(y)N_(z)), lanthanum oxide (e.g., La₂O₃), lanthanumaluminum oxide (e.g., LaAlO₃), zirconium oxide (e.g., ZrO₂), zirconiumsilicon oxide(e.g., ZrSiO₄), zirconium silicon oxynitride(Zr_(w)Si_(x)O_(y)N_(z)), tantalum oxide (e.g., TaO₂, Ta₂O₅), titaniumoxide (e.g., TiO₂), barium strontium titanium oxide (e.g.,BaTiO₃—SrTiO₃), barium titanium oxide (e.g., BaTiO₃), strontium titaniumoxide(e.g., SrTiO₃), yttrium oxide (e.g., Y₂O₃), aluminum oxide (e.g.,Al₂O₃), lead scandium tantalum oxide (Pb(Sc_(x)Ta_(1-x))O₃), and leadzinc niobate (e.g., PbZn_(1/3) Nb_(2/3) O₃). The high-k dielectricmaterial may further include dopants such as lanthanum and/or aluminum.The stoichiometry of the high-k dielectric material may vary. In variousembodiments, the lower gate dielectric 108 may have a thickness in therange of about 5 nm to about 9 nm.

A floating gate or node 112 includes a conductive material such aspolysilicon or doped polysilicon. The floating gate 112 may include athickness of between about 1 to about 10 nm. An upper dielectric 114 isformed on the floating gate 112. The upper dielectric 114 may includethe same or different materials as the lower dielectric 108. The upperdielectric 114 may include a thickness of between about 8 to about 12nm.

In one or more embodiments, a gate conductor 116 may be deposited overthe upper dielectric 114. The gate conductor 116 may include a workfunction layer (not shown) that may be conformally deposited by ALDand/or CVD. The work function layer may be a nitride, including but notlimited to titanium nitride (TiN), hafnium nitride (HfN), hafniumsilicon nitride (HfSiN), tantalum nitride (TaN), tantalum siliconnitride (TaSiN), tungsten nitride (WN), molybdenum nitride (MoN),niobium nitride (NbN); a carbide, including but not limited to titaniumcarbide (TiC), tantalum carbide (TaC), hafnium carbide (HfC), andcombinations thereof. The work function layer may have a thickness inthe range of about 1 nm to about 11 nm, or may have a thickness in therange of about 2 nm to about 5 nm.

In one or more embodiments, the gate conductor 116 may further include athin a gate metal layer (not shown) which may be formed on the workfunction layer, where the gate metal layer may include a thin layerconformally deposited on the work function layer. The gate conductor 116is deposited and patterned to form a gate electrode that may includetungsten (W), aluminum (Al), titanium nitride (TiN), cobalt (Co), etc.or combinations thereof. In various embodiments, the gate dielectriclayer 108, the floating gate 112, the upper dielectric 114 and the gateconductor 116 (and layers thereof) may be etched/patterned in a same ormultiple etch processes., e.g., reactive ion etching (RIE).

The floating gate 112 is electrically isolated to create a floating node(112). The floating node 112 may be charged using the gate conductor116, which is deposited above the floating gate 112 and electricallyisolated from the floating gate 112. The gate conductor (or conductors)is capacitively coupled to the floating gate 112. Since the floatinggate 112 is completely surrounded by highly resistive material, thecharge stored in the floating gate 112 remains unchanged for a period oftime. Fowler-Nordheim tunneling, hot-carrier injection mechanisms,induction, etc. may be employed as mechanisms to modify the amount ofcharge stored in the floating gate 112.

The amount of charge of the floating gate 112 is employed to adjust athreshold voltage in accordance with an amount of stored charge. Thepresent principles provide a floating gate structure 100 that iscompletely compatible with standard CMOS processing. The floating gatestructure 100 may be employed in hardware neural networks that can beformed on a chip alone or integrated with other structures and devices.The gate structure 110 may further include spacers, a gate cap and otherstructures depending on the device type and design.

In one illustrative embodiment, Vdd may equal 1V and the lowerdielectric 108 can store 2 microF/cm² with leakage of about 1×10⁻³A/cm². Charge stored at full 1V equals about 2×10⁻⁶ C/cm². Each accessof the device 100 may be assumed to be about 1 ns and hot electrons canprovide 0.1 A/cm² current so that a charge of 1×10⁻¹° C. can beachieved. In this case, it will take 20,000 cycles to fill in thecapacitor (floating gate 112). In such a case, 20,000 cycles would beneeded to achieve a maximum threshold voltage. The lower dielectric 108,the floating gate 112, Vdd, etc. may be modified to permit differentnumbers of cycles so that that the threshold voltage may be more or lessfinely tuned.

In other embodiments, the floating gate or node 112 can be completelycharged and discharged after every cycle to lower threshold voltage. Forexample, ˜1 ms may be needed for a complete discharge (to empty thecharge). This employs, e.g., 1 million cycles of 1 ns each to completelydischarge the device 100. Other configurations are also contemplated.

In accordance with the present principles, the floating gate transistordevices 102 can be programmed and reprogrammed with charge storagevalues to provide a smart logic device. The floating gate transistordevices 102 may be provided in a memory array, processor or any othersuitable device. Each floating gate transistor device 102 can beadjusted to, e.g., to have a threshold voltage bias (preferential pathor paths (a set of paths). Each floating gate transistor device 102 canbe individually programmed during a pulse sequence or sequences and canbe reprogrammed during a reset sequence to further update the thresholdvoltages.

Referring to FIG. 3, an illustrative node network for cognitive learning200 is provided in accordance with one illustrative embodiment. Thenetwork 200 includes a plurality of nodes 202, which are connected bylinks 208. Each node 202 may include smart logic devices, e.g.,cognitive learning device 10 (FIG. 1) for biasing a path within thenetwork 200. For example, if a given path 210 through the network isselected multiple times, the path will be biased for the next selectionby altering the threshold voltages of the active devices (transistors)in the path 210. The path 210 between input 204 and output 206 canchange with the selection of different nodes 202. The nodes 202 may alsoinclude other circuitry to perform a process step, a sequence, run analgorithm, etc.

Using the above example, network 200 may be employed for imageprocessing to identify a pattern or object in an image. Each node 202may represent an image processing step. To find an image of a car, apath 210 is found to provide the needed processing steps or algorithms.After successive progressions of executing the network or network paths,object recognition of cars is employed a greater number of times thanother object types. This biases the path 210 so that a next time thenetwork is employed, the initial process sequence defaults to path 210to reduce access and execution time based on a probability that the nextobject to be identified will be a car. Each node 202 can be selectedbased on any suitable criteria including but not limited to frequency ofaccess, lack of access, user selection, duration of access, etc.

Referring to FIG. 4, a method for employing a cognitive learning deviceis illustratively shown in accordance with an exemplary embodiment. Insome alternative implementations, the functions noted in the blocks mayoccur out of the order noted in the figures. For example, two blocksshown in succession may, in fact, be executed substantiallyconcurrently, or the blocks may sometimes be executed in the reverseorder, depending upon the functionality involved. It will also be notedthat each block of the block diagrams and/or flowchart illustration, andcombinations of blocks in the block diagrams and/or flowchartillustration, can be implemented by special purpose hardware-basedsystems that perform the specified functions or acts or carry outcombinations of special purpose hardware and computer instructions.

In block 202, a path is initially selected randomly among a plurality ofinput paths. Each input path has at least one transistor. The transistorincludes a storage capability so that accesses or usage frequency (orother characteristics) can be counted or monitored. In block 204, acorrect input path is determined for performing a current task. Thisdetermination may be made after the computation runs, and it isdetermined that the randomly selected path was not correct. For example,if the cognitive learning device is run on a computer, the computer willeventually determine the correct path based on the computation run. Inone example, for identifying an object in an image, the correct inputpath may be determined to be correct only after an incorrect path orpaths are run and results are obtained by running a path or algorithmfor the wrong object type.

In block 206, a threshold voltage of the at least one transistorassociated with the correct path is modified to bias selection of thecorrect path in subsequent accesses. This occurs after the correct pathis selected for a given task. The path selection activates the path andthe threshold voltage is modified by each access. The more theaccessing, the greater the change to the threshold voltage and thegreater bias for that path or set of paths.

The at least one transistor device may include a non-volatile randomaccess memory having a floating gate as storage capacity. The thresholdvoltage is modified by charging or discharging per access to altercharacteristics of the at least one transistor device. The at least onetransistor device is charged or discharged initially to reset the inputpaths. The at least one transistor device may include other methods formodifying its characteristics. For example, a channel resistance orother characteristic may be modified.

In block 208, a path is selected with the highest level of modificationfor a next access. In block 210, blocks 204, 206 and 208 are repeateduntil a reset is needed. In block 212, a reset may be performed: after aduration has elapsed, randomly or after one or more of the transistordevices has achieved a maximum or minimum charge storage. If a reset isneeded, the transistor storage is fully discharged or charged andprocessing returns to block 202.

In some embodiments, device biasing may be performed manually byidentifying preferential devices or paths and inputting a bias charge ofamount. In this way, the charge may be programmed manually by allottinga charge or discharge to bias the path or paths.

Having described preferred embodiments for smart logic devices (whichare intended to be illustrative and not limiting), it is noted thatmodifications and variations can be made by persons skilled in the artin light of the above teachings. It is therefore to be understood thatchanges may be made in the particular embodiments disclosed which arewithin the scope of the invention as outlined by the appended claims.Having thus described aspects of the invention, with the details andparticularity required by the patent laws, what is claimed and desiredprotected by Letters Patent is set forth in the appended claims.

What is claimed is:
 1. A cognitive learning device, comprising: a plurality of inputs, each input including an input path having at least one transistor device having a storage capacity; and a circuit responsive to the plurality of inputs and selecting an input set in accordance with a current task; wherein the input set selected changes at least one voltage threshold to bias a selected path of a plurality of paths for subsequent processing.
 2. The device, as recited in claim 1, wherein the input set decreases a threshold voltage in at least one path that is not selected.
 3. The device, as recited in claim 1, wherein the at least one transistor device includes a non-volatile random access memory having a floating gate as the storage capacity.
 4. The device, as recited in claim 3, wherein the floating gate is charged or discharged per access to alter a threshold voltage of the at least one transistor device.
 5. The device, as recited in claim 1, wherein the circuit includes a comparator.
 6. The device, as recited in claim 5, wherein the comparator randomly selects one of the input paths to determine whether the path is correct and if correct usage of the path modifies the characteristic of the at least one transistor device.
 7. The device, as recited in claim 1, wherein the at least one transistor device is charged or discharged initially to reset the device.
 8. The device, as recited in claim 1, wherein the input set includes at least one input path.
 9. The device, as recited in claim 1, wherein the at least one transistor device includes an analog device.
 10. A cognitive learning device, comprising: a plurality of inputs, each input including an input path; at least one transistor device associated with each input path, the at least one transistor device having a storage capacity such that a threshold voltage of the at least one transistor device is modified in accordance with access criteria; and a comparator circuit being responsive to the plurality of inputs and selecting an input set in accordance with a current task such that the input set selected changes at least one voltage threshold to bias a selected path of a plurality of paths for subsequent processing.
 11. The device, as recited in claim 10, further comprising: decreasing a threshold voltage in at least one path that is not selected.
 12. The device, as recited in claim 10, wherein the at least one transistor device includes a non-volatile random access memory having a floating gate as the storage capacity.
 13. The device, as recited in claim 12, wherein the floating gate is charged or discharged per access to alter the threshold voltage of the at least one transistor device.
 14. The device, as recited in claim 10, wherein the comparator randomly selects one of the input paths to determine whether the path is correct and, if correct, usage of the path modifies the threshold voltage of the at least one transistor device.
 15. The device, as recited in claim 10, wherein the at least one transistor device is charged or discharged initially to reset the device.
 16. The device, as recited in claim 10, wherein the input set includes at least one input path.
 17. The device, as recited in claim 10, wherein the at least one transistor device includes an analog device.
 18. A method for employing a cognitive learning device, comprising: randomly selecting a path initially among a plurality of input paths, each having at least one transistor; determining a correct input path for performing a current task; and changing at least one voltage threshold to bias a selected path of a plurality of paths for subsequent processing.
 19. The method, as recited in claim 18, wherein the at least one transistor device includes a non-volatile random access memory having a floating gate as the storage capacity, the method further comprises charging or discharging per access to modify the threshold voltage of the at least one transistor device.
 20. The method, as recited in claim 18, wherein the at least one transistor device is charged or discharged initially to reset the input paths. 